Etching-machine



H. C. ALLEN.

ETCHING MACHINE.

APPLICATION FILED JULY 6.1920.

1 89,284. Patented Aug. 30, 1921.

5 SHEETS SHEH I.

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ETCHING MACHINE.

APPLICATION mgn JULY 6.1920.

1,389,284. Patented Aug. 30, 1921.

5 SHEElS-SHEEI 3.

vwamtoz [If d/i/ZoWZ H. C. ALLEN.

ETCHING MACHINE.

APPLICATION FILED JULY 6,1920.

1,389,284. Patented Aug. 30, 1921.

5 SHEETS SHEET 4.

H. c. ALLE N.

ETCHtNG MACHINE.

APPLICATION FILED JULY 6,1920

1,389,284. Patented Aug 30, 1921.

5 SHEETS-SHEEI 5.

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HERBERT CLIFTON ALLEN, 0F RICHMOND, VIRGINIA.

ETCHING-MACHINE.

Application T 0 all whomz't may concern:

Be it known that I, HERBERT C. ALLEN, a citizen of the United States, residing at Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Etching-Machines; and I do declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use the same.

This invention relates to machines adapted to mechanitally remove the surface coating from a plate to be etched, the actual removal of the metallic face of the plate being accomplished in an acid bath in the usual well known manner.

The invention is an improvement upon Patent 1,U39,T13, granted October 1, lJlEl to W. S. Eaton, the improvements residing particularly in the mechanism by which a needle which operates upon the surface of the plate to he etched is moved in and out of engagement with the plate.

In the machine disclosed by the Eaton patent and in other similar types of machines a stylus is operated by a hand move ment over a pattern or master plate and this causes a corresponding movement needle over the prepared work plate, the needle being moved into and out of engagement with the work plate by a foot movement which is altogether independent of the hand movement of the stylus over the pattern plate. In order to obtain a high degree of excellence of the work produced by such a machine, considerable practice is necessary to produce the necessary skill. The present invention eliminates the foot movement which moves the needle in and out of engagement with the work plate and makes the required movement of the needle auto matic upon. the movement otdhe stylus in and out of engagement with the pattern plate. it will thus ill, 1'Pll that the in:- provcd liilc lilll can he oprratcd ll unskilled ah r and withoutfirst ic pnriuzi underalile practice) and cxpcricncc.

it omit-merit of the m dlr in with the w n it plntc ch):'tvomaghoth an in ludes the slylu; and

\ are arranged to permit which the nee: l l e Specification of Letters Patent.

of a

Patented Aug. 30, 1921.

filed July 6, 1920. Serial No. 394,322.

ment with the work plate when the stylus is moved by hand into engagement with the pattern plate.

Various ways in which to electromagiietically operate the needle may be employed, but is is preferable to employ the important feature of invention wherein primary and secondary circuits are used, the primary circuit including the stylus and pattern plate and being comparatively weak so that no appreciable amount of sparking will occur when closing or opening this circuit by enagement or disengagement with the pattern plate.

With the above and other aims and objects in view. the invention consists of the novel features of construction, and the combination and arrangement of parts as are hereinat'tcr fully described and claimed.

The accompanying drawings illustrate the practical embodiments of the invention. In these drawings, Figure 1 is a side elevation of a machine constructed in accordance with the invention.

Fig. 2 is a front elevation of the machine.

Rig. 3 is a. diagranunatic view illustrating the circuit arrangement of the improved mechanism.

Fig, l is a detail sectional view taken substantially on the line 4-4 of Fig. 1.

Fig. 71 is a plan view of the magnet which is employed to move the needle out of engagement with the work plate and Showing particularly the mounting for the magnet.

Fig. 3 is an end view of the relay which is employed in the improved mechanism.

Fig. T is a top view of the relay.

Fig, 8 is a side elevation of the machine equipped with a modified form of mechanism for moving the needle in and out of engagemen with the work plate.

Fig. is a diagrammatic view illustrating a the modified form.

in the drawings. i-spccially in Figs. 1. 2 and a. an i'tcnin r machine constructed simitla: dis loscrl in the above iotou patent is conventionally 1 s a atiug the th s a cine .vhich 143ml top plate 3.

"ato l. (W or n-J up the lath-z men in iw osnai manner Bolted or otherwise suitably secured to the top plate 3 and rising vertically therefrom is a column 4, the upper end portion of which supports a fixed frame 5 and a fixed work bed 6. This work bed 6 is provided with suitable means 7 designed for receiving and holding in place a work plate 3, the latter having a. metallic face a surface coating adapted to have portions removed to allow the exposed portions of the metallic face to be subjected of an acid bath in the usual and well known manner.

Movably mounted upon the fixed frame 5 is a carriage 9.!One end of the carria e 9 is provided with an upstanding lug 10 w iicli fits into the bottom or intermediate portion of a substantially U-shaped bracket or yoke he spaced arms of this bracket 11 adjacent their lower connected ends are provided with pintles 12 which .t'orm the pivot of an arm 13. The pivot of this arm out of wood.

the longer part is provided at its end with a needle 14 operable over the work plate 8. The arm 13 is consequently overbalanced to t e position where the needle 14 is in engagement with the work The upper arms of the bracket 11 are provided with alined pintles 15 which serve as a plate 16 carries the magnetic core 18 lower extremity posed a short distance above the upper edge of the arm 13 and in alinement with a magnetic plate 20 mounted thereon. The arm 13 when attracted by the magnet 17 will be held in a raised position so that the needle 14 is out of engagement with the work plate t, but when the magnet 17 is dc'c'nergized the arm 13 will drop by gravity so that the needle 14 will engage the plate 8. The magnet 17 being carried by the pivotally hung 16 may be moved rearwardly and upwardly away fromthe arm 13, but when it is disposed in its normal position the plate 16 rests upon inwardly extending lugs 21 which are formed integral with the anus of the bracket 11 at the upper extremities of said arms. The bracket 11 is locked to the alorcmeutioned lug 10 by means of a set screw :22.

In order that the arm 13 may be held and locked in its raised position with the needle it out of engagement with the work plate the forward side of the bracket 11 has pivorally mounted thereon a cam lever 23 en- Q'HQQIllllC with the arm.

Mounted upon the column 4 is a sleeve 24 having a yol 25 to which is hunp so as to have a universal movement a transmitter or arm 2&3. The transmitter .26 is hung upon the yoke 25 at a point between its ends.

' parts discloses a foot operated rod from the metal the mach' All of the arts above described exception of tli and possibl the cam lever 23 are similar to tlie machine disclosed in patent. This patent in addition constructed the Eaton to these for raismg the arm 13 so that the needle 14 is held out of engagement with the work This rod has con omitted from the present invention and the same result r is accom- 0t Th her terminal of the magnet 17 is connected by the conductor 31 to an adjustable relatively fixed contact 32 of a relay mechanism 33 which is mounted upon one of the side boards 2 of the supporting frame work 1. he numeral 34 designates the movable armature of the relay. This is pivoted in any suitable manner at one end upon a suitable by means of a spring 36, one end of which is engaged by a set screw 37 mounted upon a bracket fixed to the base of The pivoted end of the armature 34 is connected by a conductor 38 to a spark condenser 39, which in turn,- is connected by a conductor 40 to the source of current. This circuit is comparatively strong so that the magnet 17 when energized will have strength sutli he position is out of engagement with the work plate 8. This circuit may be termed the major circuit.

The other 33 consist of a pair of electromagnets 41 arranged to operate in unison and mounted upon a suitable bracket carried by the base of the relay. One terminal of this pair of magnets 41 is connected by a conductor 42 to the set screw 43 which holds the master or pattern plate holder 29 upon the top plate 3 of the supporting frame work 1 so that an electric connection is made to the master or pattern plate 28. The other termina of this pair of nL-igncts 41 is connected by a conductor to one pole of a. battery 45. the other pole of which is connected by a conductor the securing post 47 of the column 4 so that an electric connection is made to the stylus :5? through the medium of the metal parts of the machine carried and supported by the column 4. This circuit may he termed the primary or minor circuit.

In using the machine above described, assuming that the work plate 8 is clamped in place, that the master or pattern plate 28 is clamped in place, and that the machine has been adjusted to reproduce the design of the master or pattern plate in the desired size upon the work plate, it is only necessary for the operator to move the stylus 27 into contact with the master or pattern plate 28 and trace the lines or design thereon. In doing so the stylus will be brought in and out of engagement with the master or pattern plate. Every time the stylus engages the pattern plate the primary or minor circuit is closed, the current passing from buttery 45 through conductor 46, the metal parts of the machine, stylus 2?, pattern plate :18, conductor 42, magnets 41 and conductor 44. lul'ck to the battery. The primary or minor circuit being; closed. the magnets 41 will be energized so as to lift the armature 34 out of engagement with the fixed contact 32. Normalty the armature 34 is in engagement with the contact 32 vso that the major or second ary circuit is closed, thus causing the magnet 17 to be energized and holding the arm 13 to the position where the needle 14 is out of engagement with the work plate 8. W hen the magnet 17 is deenergized the armature 34 is raised out of engagement with the contact 32, the arm 13 will drop by gravity to the position where the needle 14 is in engagement with the work plate 8. It will thus be seen that the raising and loweringr of the arm 13 carrying the needle 14 out and in engagement with the work plalc is entirely automatic. upon the movement of the stylus 27 out and in engagement with the pattern plate 28. The primary or minor circuit having the battery 45 as a source of current is comparatively weak so that no shock will be obtained in operating the ma chine and so that no sparking will occur or fusing will take place when the stylus 27 is bmught into and out of engagement with the pattern plate 28. The spark condenser 39 arranged in the secondary or major circuit serves to prevent an appreciable amount of sparking to take place between the armature 34 and fixed contact 32 when the armature is moved in and out of engagement with the contact.

In the modified form of the invention shown in Figs. 8. l) and 11! the same refercncc numerals are used to indicate the usual parts ill the Eaton etching machine as are used in the other figures ol' the drawings. In this modified form the bracket 11 has been eliminated and in its place is used the ordinary bracket 11' of the Eaton machine. The arm 13 is constructed similar to and pivoted to the bracket 11 in the manner disclosed by the Eaton patent In this case a. lifting rod in is employed. This lifting'rod 45 is similar to the lifting rod employed in tho Eaton machine as it engages the lower side of the arm 13 and under the tension of the spring 49 normally holds the arm 13 so that the needle 14 is out of contact with the work plat'e 8. Instead of having the rod 48 connected to a foot treadle as in the Eaton patent, the. lower end of this rod is provided with a magnetic head 5U arranged directly above. the upper end of the magnetic core 51 of an elcctromagnet 52 which is carried by the bracket 53 mounted upon one of the side boards 2 of the framework 1.

In this form oi the invention a relay 33' is used. the pair of magnets ll of which have one of their terminals connected by conductor l2 to the pattern plate while their other terminal is connected by the conductor -14 to one pole of a battery 45'. the other pole of which is connected by a conductor 46' lo the body of the column 4 and through the metal parts of the machine to the stylus :27. This circuit is substantially the same as the primary or minor circuit in the first described form of the invention.

The secondary or major circuit in the modified form includes the elcctromagnct 52. One terminal of this is connected by a conductor 30' to a source of current, while the other terminal is connected by a conductor 31' to a spark condenser 39' which in turn is connected liy a comluctor Z-lH to illuhracket 35 upon which an armature ill is pivotally mounted. The free end of the armature 34 is cngagcable with an adjustable relatively lixcd contact 32. which is connect rd l a conductor in in the source of (\II' rent of the major circuit. Under normal conditions that is. when the primary or minor circuit is open so lhal the magnets ll are dci ncll 'ncd. armature 34' is out of cugagement with the conta t 32 under the tension of set screw 3?" acting against spring 36' so that the major circuit is also open and the magnet 52 is dei ncrgizcd. Under these conditions. the sprin g 49 maintains the rod is in raised position so that the arm 13 is raised with its needle 14 out of cngagenu-nt with lhe work plate a. When, however, the operator moves the stylus 527 into engagement with the pattern plate 28 the primary or minor circuit is closed. thus energizing the magnets 41 and lifting the armature 34' into engagement with the contact 32. This movement of the armature ii-l closes the secondary or major circuit and energizes the magnet :32. The energizatiou of the magnet 52 will draw the rod 4% downwardly against the tension of the spring 4%? and permit the arm 13 to drop by gravity to the position where the needle 14 engages the work plate The instant the stylus 2? is raised from the pattern plate 28 the primary circuit will be opened. which condition will permit the armature 34' to break the secondary or major circuit, thus dei nergizing the magnet 52 and permitting the rod 48 to raise the arm ill. The primary circuit being comparatively weak as in the previous case will not permit sparking to occur when the stylus 27 is moved into and out of engagement with the pattern plate 28, and the spark condenser 39 will not permit an appreciable amount of sparking between the armature 34 and contact 32 as the armature is moved into and out of engagement with the contact.

From the foregoing description, taken in connection with the accompanying drawings, it will be seen that the objects of the invention have been effectively carried out. The movement of the needle in and out of en gagement with the work plate is entirely automatic and instantaneous by reason of the fact that it is controlled solely by the movement of the stylus in and out of engagement with the pattern plate. The necessity of a foot operated treadle has entirely been dispensed with. The operation 01 the improved machine is easy and perfect work may be turned out by unskilled labor without first requiring considerable practice. Furthermore, a greater output may be obtained by using the improved machine than could be obtained by using the usual type of machine.

It is obvious that numerous changes in form, proportion, and in the minor details of construction may be resorted to without departing from the underlying principles of the invention as defined in the appended claims:

1. In a machine of the class described, the combination of a work bed adapted to hold a work plate, a holder adapted to hold a pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus operable upon the pattern plate and movable in and out of engagement therewith, mechanism asso ciated with said stylus and said needle for moving said needle over said work plate upon movement of said stylus over said pattern plate, and electrically operated means for moving said needle in and out of engagement with said work plate. the circuit of said means including said stylus and said pattern plate, whereby said circuit is o )ened and closed upon movement of said stylus in and out of engagement with said pattern plate.

2. In a machine of the class described, the combination of a ark bed for holding a work plate, a holder for holding a pattern piate, a needle operable upon the work date and movable in and out of engagement t erewith, a stylus operable upon the pattern plate and movable in and out of engagement therewith, mechanism associated with said needle and said styius for causing said needle to operate upon said work plate upon movement of said stylus upon said pattern plate, means for moving said needle in and out of engagement with said work plate and including an electromagnet, the circuit of said magnet including said stylus and said pattern plate whereby said circuit is controlled by movement of said stylus in and out of engagement with said pattern plate.

3. in a. device of the class described, the combination of a work bed for holding a work plate, a holder for holding a pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus o 'ierablo upon the pattern plate and movable in and out of engagement therewith. means associated with said needle and said stylus for operating said needle upon said, work plate upon movement of said stylus upon said pattern. plate, electromagnetic-ally operated means for moving said needle in and out of engagement with said work plate, a circuitfor said means, a relay having its armature arranged in said circuit, a secondcircuit including the electromagncts of said relav and said stylus and said pattern plate, whereby said second circuit is controlled by the movement of said stylus in and out of engagement with said pattern plate.

4. In a machine of the class described, the combination of a. work bed for holding a work plate, a holder for holding a pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus operable upon the pattern plate and movable in and out of engagement therewith, means associated with said needle and said stylus for operating said needle upon said work plate upon a movement of said stylus upon said pattern plate, a normall energized electromagnet for normall holding said needle out of engagement with said work plate, said magnet when deenergized permitting said needle to move into engagement with said work plate, and means operable when said stylus is moved into engagement with said pattern plate to definergize said magnet.

5. In a machine of the class described, the combination of a work bed for holding a work plate, a holder for holding a pattern plate, a needle operable I1 0l1 the work plate and movable in and out o engagement t ierewith, a stylus operable upon t 1e pattern )liltfl and movable in and outofengagement t erewith, means associated with said needle and said stylus for operating said needle up said work plate upon a movement of sa d stylus upon said pattern plate, a normalt energized electromagnet for normally ho] ing said needle out of mag ement with said work plate, said magnet w en deenerg ized permitting said needle to move into engagement with said work plate, a circuit for said magnet, said circuit including a normally closed switch, a second circuit including said stylus and said pattern'plate and closed and opened by the engagement and disengagement respectivelyof said stylus with said pattern plate, and electromagnetic means included in said second circuit for opening said switch when said second circuit is closed.

6. In a machine of the class described, the combination of a work bed for holding a work plate, a holder for holding a. pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus operable upon the pattern plate and movable in and out of en gagement therewith, means associated with said needle and said stylus for operating said needle upon said work plate upon a movement of said stylus upon said pattern plate, a normally energized electromugnet for normally holding said needle out of engagement with said work plate, said magnet when denergized permitting said. needle to move into engagement with said work plate, a circuit for said magnet, said circuit including a normally closed switch, asecond circuit including said stylus and said pattern plate and closed and opened by the engagement and disengagement respectively of said stylus with said pattern plate, and electromagnetic means included in said second circuit for opening said switch when said second circuit is closed, said second circuit being comparat vely weak so that no sparking will occur when said stylus is engaged and disengaged with said pattern plate.

7. In a machine of the class described, the combination of a work bed for holding a work plate, a holder for holding a pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus operable upon a pattern plate and movable in and out of engagement therewith means associated with said needle and -aid for mm ing said needle upon said w t u as said stylus is moved upon said pal a maer circuit, an electromag T. in said major circuit for hol u i ii of ei'nragement with -i uit includ ing said '2 plate, sa d i'ninor circ ii phi stylus is Kim cd ir hi 7 patt rn plate, and a w-i i hiare ir'hnl'nl in i maturg is in:

8. In a machine of the class described, the combination of a work bed for holding a work plate, a holder for holding a pattern plate, a needle operable upon the work plate and movable in and out of engagement therewith, a stylus operable upon the pattern plate and movable in and out of engagement therewith, means associated with said needle and said stylus for moving said needle over said work plate as said stylus is moved over said pattern plate, a pivotally mounted arm upon which said needle is carried, a magnetic plate fixed to said arm, an electromagnet mounted upon the machine and disposed above said magnetic plate whereby to hold said arm in the position where said needle is out of engagement with said work plate, a circuit for said magnet, and means for opening said circuit upon engagement of said stylus with said pattern plate.

5). In a machine of. the class described, the combination of a work bed for holding a work plate, a holder for holding a pattern plate, a movable carriage, a stylus operable upon said pattern plate and movable in and out of engagement therewith. means asso ciated with said stylus and said carriage for moving said marriage upon movemen of said stylus upon said pattern plate. a bracket carried by said carriage, an arm pivoted to said bracket, a needle carried by said arm and operable upon said work plate. :1 supporting plate pivotally mounted upon said bracket, an electromagnet carried l4 said supporting plate for holding said arm. in the position where said needle is out of engagement with said work plate. means carr ed by said bracket for maintaining said, supporting plate in the position where said magnet is disposed in operative relation with respect to said arm, said means per'uitting said snpporting plate and said magnet to be swung out of operative position with said arm, a circuit for said magnet, and means for opening said circuit when suio stylus is moved into Qi'gdgQlURHt with said pattern plate.

i l. in a nuwhine or" i li' class described, the combination of" a stylus arm, :1 primary eiew'trhcircuit oerable in. said stylus arm, an electric n-lu; controlled by said prinuiry ircuit. a Emilio arm. :1 soijuliduly electric i mluy. and electric ,i uilii, for operatvir rnit romroii means in 1 me said Tn tesi-nnw my band.

hereof have hereunto set l'lllliiiiii 'l' t'lih'lf 'ibl ALLEN.

It is hereby certified that in Letters Patent No. 1,389,284, granted August 30,

1921, upomthe application of Herbert Clifton Allen, of Richmond Virginia, for an improvement in Etching-Machines, errors appear in the printed specification requiring correction follows: Page 1, line 60, for the worii is, first occurrence, read it; page 3, line 32, a.fter the word "denergized" insert the Word when 'end that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

i'Signed and sealed this 15th day of November, A. D., 1921.

[BEAI n] KARL FEN NG,

rioting Commissioner of Patents. 

